Category Archives: Faculty Voices

All stars are not created equal. When you look out into the night sky, you are seeing all sorts of unique and interesting objects. Some stars are small and cool (at least, compared to our Sun), and live for many billions of years. Others have evolved and inflated to enormous sizes- even over 1,000 times the size of our sun. There is a class of bright, blue stars called “Classical Be stars” that are between about 5 – 20 times more massive than the sun, and spin so quickly that they are nearly torn apart by the resulting centrifugal force. These stars also have disks that grow and shrink, appear and disappear. Classical Be stars are unique in astronomy, because their disks originate from the stars themselves. Material from the surface of the star is flung outward with so much speed (and angular momentum) that it is launched into orbit, and then settles into a disk in an event called an “outburst”. Lehigh physics professor Joshua Pepper and graduate student Jonathan Labadie-Bartz are studying these objects because there is still much that is unknown, especially regarding the physical mechanisms behind outbursts. The header shows an artist’s rendition of a Be star and its disk.
As a Classical Be star experiences changes, whether it be an outburst or a shrinking disk, the amount of emitted light will change too. If you look at these stars every night for many years, and record how their brightness is changing, then you can read these signals and interpret what the star is doing. This is the main idea behind the research. The brightness measurements come from the Kilodegree Extremely Little Telescope (KELT), directed by Prof. Pepper. KELT is a survey that has been monitoring large patches of the night sky every clear night for the last ten years, and is being used to discover new planets orbiting these distant stars. So far, KELT has observed over 4.4 million stars. These show lots of interesting behavior, providing many opportunities to explore new science, including the study of Classical Be stars.

John Spletzer is an Associate Professor of Computer Science and Engineering at Lehigh University. Below he details the

The inspiration for this project came during my sabbatical at Love Park Robotics, LLC (LPR) in 2015. LPR is a robotics startup doing work in industrial perception, and the primary project I worked on was a vision-based pallet detection system for use by Automated Guided Vehicles (AGVs). AGVs are autonomous vehicles operating in warehouse environments. Think “robot forklift,” and you have the right idea. To estimate their position and orientation, AGVs typically rely upon 2D LIDAR (laser scanner) based localization systems that track reflector targets surveyed into the warehouse. The approach is very effective, and can provide sub-centimeter levels of accuracy. However, the process of installing the targets is both time consuming and expensive. Furthermore, it needs to be repeated any time the warehouse is reconfigured. Conversations with Tom Panzarella, CEO of LPR, lead us to investigate an alternative approach. Our hypothesis was that recent advances in 3D LIDAR systems would allow us to estimate AGV pose by tracking natural features already existing in the warehouse. This would eliminate the need for retroreflector targets all together. We refer to this technology as AGV-3D. From my NSF CAREER research, my lab had already demonstrated that a smart wheelchair system using a similar approach could reliably navigate in an urban environment without GPS. You can see an early video from the project here:

Jill McDermott is an Assistant Professor in the Department of Earth and Environmental Sciences at Lehigh University. Her research is taking her to the high Arctic to explore for new volcanic activity and ecosystems on the seafloor. Follow along live on the cruise blog.

NASA’s mission to the ice-covered ocean of Jupiter’s moon Europa will launch in the 2020s. About a decade from today the first data return may arrive, but in the meantime there is plenty to do on our own planet. This week, I join a rare mission on the German icebreaker Polarstern to do the next best thing – a search for submarine hydrothermal vents in the Arctic Ocean. Our goal is to reveal the chemical signatures that accompany life on the seafloor, and track these signals upward through the ocean water to the overlying ice-water interface, and into the ice itself. The idea is to discover an extreme ecosystem living below the Arctic ice to understand how to design a mission for a future space lander. This well-informed lander will make similar measurements while looking for life on Europa’s icy surface.

At 87°N 61°E in the Arctic, two of Earth’s tectonic plates diverge along an underwater volcanic mountain chain called the Gakkel Ridge, which stretches for 1,100 miles off Greenland towards Siberia. The plate motion here is the slowest in the world, spreading apart only 0.4 inches per year, at a rate 3 times slower than your fingernails grow. Due to this low tectonic activity, it seemed unlikely that the Gakkel would host hydrothermal vents – places where seawater circulating through fractures in the seafloor rock extracts heat derived from volcanic activity, and rises up to the seafloor in scalding plumes of mineral-laden water. These vents deliver chemicals to the seafloor that provide energy and building materials for specialized ecosystems, a process called ‘chemosynthesis.’ In 2003, however, a team of shocked scientists discovered chemical signatures in the water indicating multiple regions of hydrothermal activity along the Gakkel Ridge.

All scientific research requires patient dedication, and this expedition builds on years of risks, set-backs, and successes of many colleagues. The deep ocean is harsh. The freezing waters of the Arctic are even less forgiving than the mid-latitudes, and little is known about the seafloor ecosystems that are living there, undetected for tens of millions of years. In the coming weeks, I may be among the fortunate few to collect the first samples at the seafloor at one of the Gakkel vent sites.

We are aiming for a particular location in the Arctic, the Karasik Massif, an underwater mountain that rises rapidly from 15,400 feet depth to 1,850 feet depth. The Karasik Massif lies along a fault, a break in the seafloor rock that cuts through thin ocean crust into underlying ‘ultramafic’ rocks that formed deeper in Earth’s mantle.

The ultramafic geologic setting makes this site an exciting target for exploration due to the geochemistry that arises when circulating fluids interact with iron-rich rocks at high temperatures and pressures. Similar conditions exist at two other known hydrothermal fields in the Atlantic Ocean, Lost City and Rainbow, where vent fluids expelled at the seafloor are rich in dissolved hydrogen gas. The enrichment in hydrogen gas means there is great potential for the chemical, or ‘abiotic’ formation of organic molecules like methane and formic acid – possible precursors to the prebiotic compounds from which life on Earth emerged. There are only a few well-characterized seafloor ultramafic vent sites, however, and every one is different. This expedition is vital to understand the full range of chemical and biological diversity possible around Earth’s chemosynthetic ecosystems.

One challenge to studying the chemistry of modern vent fluids is that living things now permeate our planet. Organic compounds can also be generated and consumed by life itself, of course, and active microbial communities living in the seafloor around the vents rely on chemical energy from compounds emitted by the vents, such as hydrogen and methane. My goal on this expedition is to collect vent fluids and characterize their geochemistry, including distinguishing abiotic from biotic chemical processes, and how these influence the generation of life-related biogeochemical signatures.

To collect the vent fluids, we will launch the Nereid Under-Ice, a new remotely operated underwater vehicle developed and operated by the Woods Hole Oceanographic Institution . The Nereid UI will first be deployed in free-swimming autonomous mode to make high-resolution seafloor maps and track down the vents by measuring chemical clues, such as particle-rich water and locations where the seawater is relatively rich in hydrogen and methane. Once the exact location of the vent site is known, the Nereid UI will transform and launch again, now tethered by a fiberoptic cable the width of a human hair. I will equip it with titantium syringes that can collect vent fluid samples and maintain seafloor pressures until the samples are back onboard the ship. There my colleagues and I will begin the exciting task of understanding the origin of these fluids, how they sustain life on the Arctic seafloor, and what this means for life detection on other planetary bodies in our solar system and beyond.

Research support includes funding from the National Aeoronautics and Space Administration and the Alfred-Wegener Institute.

Kathy Iovine, an Associate Professor in the Department of Biological Sciences, and Bob Skibbens, a Professor in the Department of Biological Sciences, introduce you to their research on Roberts Syndrome. This work is funded in part by a Faculty Innovation Grant.

Greetings! The purpose of this post is to introduce you to a Faculty Innovation Grant titled Developing a vertebrate model system for Roberts Syndrome. Roberts Syndrome (RBS) is a severe form of birth defects that significantly impacts bone growth (as well as cognition and organ development). In RBS patients, the long bones of the limbs are severely reduced, along with craniofacial abnormalities (cleft palatte, small head size, etc). The syndrome arises due to mutations in a gene named ESCO2, but the basis of the ESCO2 defect remains unknown. An important step forward will be to develop a model system for RBS so that we can ultimately devise clinical therapies.

As part of a collaboration between the Skibbens and Iovine lab groups, we are establishing the zebrafish fin as an RBS model system. Zebrafish fins are an excellent system since amputation results in complete regrowth, and we have the technology to turn down gene function during regrowth (“regeneration”). We found that loss of Esco2 protein causes skeletal defects in the zebrafish regenerating fin (Figure 1 shows a normal fin skeleton). With the ability to assay for Esco2 function in regenerating fins, we are pursuing a new model that Esco2 may cause skeletal defects by regulating the expression of genes. Evidence obtained through this collaboration suggests that Esco2 regulates cs43 – a gene that encodes a protein previously shown by the Iovine lab to impact bone growth (check out Iovine et al., 2005, Developmental Biology) and implicated in a developmental abnormality referred to as Oculodentodigital dysplasia. This research has been published in the journal Developmental Dynamics (Banerji et al., 2016 Developmental Dynamics)!

More recent efforts have been to provide mechanistic insights into how Esco2 regulates the expression of the skeletal gene cx43. The most direct way to show this is to demonstrate that the Esco2 protein, or a protein regulated by the function of Esco2 (i.e. Smc3), associates with the cx43 gene. Esco2 regulates the ability of Smc3 (and others) to associate with DNA. We are now testing if Smc3 physically binds to the DNA surrounging the cx43 gene. Raj Banerji has made important progress showing that she can isolate chromatin (i.e. genomic DNA plus all of the associated proteins) from a fin cell line, AB9. She can also isolate only the parts of the chromatin that are associated with Smc3. She is now testing if cx43 DNA is among the isolated Smc3-bound chromatin.

KASHI JOHNSON is an actress, director and Associate Professor in the Department of Theatre; where she teaches courses in performance, Hip Hop theatre and directs plays. Dedicated to cultivating voices from the Hip Hop generation, Professor Johnson has been nationally recognized for her research in Hip Hop theatre pedagogy and given talks about her groundbreaking Hip Hop theater course ‘Act Like You Know’, for national speaking platforms like TEDx and BlackademicsTV.

They say if you want to tell your story, the best way to do it is to tell it yourself. Over the past year, I’ve done exactly that by gathering and organizing over 10 years worth of student devised Hip Hop theatre video performances, newspaper articles, and images that document my work in Hip Hop theatre; by collaborating with a very talented, very patient web designer, on the re-design of my YouTube channel, creation of a digital archive and design of my professional website www.kashijohnson.com.

The YouTube channel, Kashi Johnson, now features over 200 video clips of Lehigh student performances in Hip Hop theatre. The videos are organized into chronological playlists that can be easily accessed by anyone. Since the channel update, the view counts on my videos has more than doubled with 11,600 views and counting. I am pleasantly surprised at how well the channel is doing and look forward to continuing to build this archive with such a solid foundation in place.

I also worked with the same web designer to create my professional website www.kashijohnson.com . This website is my digital portfolio and it showcases my research and teaching as a theatre professor, actress, director, playwright, producer and public figure. My website has a lot of moving parts. It tells my story through images, videos and digital records of interviews, articles and performances. Since the website’s launch in May 2016, I have received a steady stream of positive feed back about the site and made several professional connections with fellow scholars interested in my work. I am encouraged and excited because this site is generating the right type of attention to my work and has empowered me to network with confidence and ease.

This link is a YouTube video that was designed for my website as a digital calling card. In the words and voice of one of my students, Karen Valerio ’17, it tells my story: who I am, what I’ve done and what I’m about to do next.

Enjoy!

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